Reaction product of silicon monoxide and ammonia and rubber compositions containing the same



' of matter comprising in Patented Jan. 19, 1954 rah OFF-Ice nmo'rronurnonnono HsmIooN, MoNoxme snowma n U BER QMKQ .isr'rlonsijoonminme THE SAMEN manias. sears o gahog zraus, Ohio, sassignor eh h shimmerlliewfiarkw ,No Drawing. Application May 26, 1-950;-=-

S .erial No. 164,619

This invention" relates '-to a novel com-p' si-tion rganic materials identical withthe reactionproducts obtained by reacting gaseous silicon monoxide with ammonia ofmatter.

It is an -obJ'e0t-1if this' inventiorr to; provide a novel compositionof matter whichis useful as; a reinforcing pigment"ior-rubbery-compositions.

' Another object-of this-'invention -is :to provide 1 a; methodof forming-a-novelcompositionofmatter which is suitable as-arubber-reinforcingpig- :mentin reiniorcing ifi-h ite and light-coloredrubbery -compositions and 'whichdoes mot-discolora white or light-colored rubbery composition to;

whichitisadded; s l fi iell'pm y i a, ac hii fine;

. r r bber-r1 0 :finl'ifiqmjih i 1 o m Qll i;

found necessary: op si ipnsmreinmrene 9 increase the rubbery compositions toimpartto these comiorcings pig- W), ,3 quirements for a reinforc ng pigment. Furthermore, it is doubtful lwhether the carbon black s industry ran-continue to supply the vast quantities -ofccarbon black ereinforcing agent'so-de- 5 manded since the-rammaterials'fiom which; carbon blacksaraproducedeareimpiciIyLbeing Idepleted. v I have-iound-anovel-composition--of matter comprising inorganic-materials-identica1- witli; thew reaction products-obtained by reacting jgasequs silicon monoxidea'nd' ammonia-With each other, jwl ich reaction products are excellent rubber re- 'in'forcing pigments when incorporated with a air-scams. (CL-136914115);

and the: method-o fmalging the :novel'composition n ifiness, resistance to positions the desirednrinforcing properties (irons beusei in accordance;with this -invention may. be almost pure whitespermitting it .to belincorporated into J White or vlight-colored rubbery. compositions without irreparablyr discoloringthe rubbery com- 5 vpositions.

The preparationoof silicon monoxide is well known sin .the..art being described in various literature. references, including U.. S. -.,Pa.ten-t ;N0. 875,286 to.;..Potter U-zl' S. A, Patent 1 No. '.90-8,131;:'-to

' U. S. \Ratent; No; 1,850,286sto Mittasch-o etal. and .U.; S.l.;l?atent \-No.;v 2,333,948, to. Muskatl, Apr.e- 'ferred;method ofr-formingngaseous siliconsmql oxide is; to; mix. a solid .silicon-bearingamaterial,

:15 such as relatively pure silica sand,;,yvith a pow- ,dered carbonaceousxfuel and to heatath m x r in a furnace orhinv an: electric arc,.in;, an, .iatrnosphere having. a relatively ,low-, ;oxy en; content, I the. gaseous; silicon .monoxide;-being formedhas ya 0- reaction product. Y

,- Upon, thereactionof gaseous silicon monoxide with ammonia, a polymeric, silicon oxyjmide haying (the 1 empiricals formula S iONH)1-,,, where a:

isianinteger, is formed;

5 The reaction. products-obtained;bylthe,-neaction of gaseous S11iQ0n; mQI1OXide .Wi;th ammonia, are ,excellent, reinforcing: pigmentsv forrrubbery comsitions. mpa t n to: the. rubb ry ompositim vphysical, propertiesaand characterise generally equivalent to .those :,;obtained when reinforcing .the; rubbery: compositions with carbon black. 1T0

; impart optimum reinforcing; characteristics it i is preferable :that- -reaction-- products having .an average particlesize-oi;from 5 to 20q millimi- Silicon monoxidqamrn onia';reaction jprodiicts may be incorporated as a rubber reinforcingingredient into any rubbery composition which is capable ot being reinforced with carbon blacks.

the rubhcr l materials apab e 5 L r i 0 mentaroin t1 r 1 ubber, uchasc outchouc and the like which," is. essentially. a. conjugated polymercofvisoprene or synthetic rubber, such; as the rubbery polymers off open-chain conjugated -rdienesvhavmgsfromm4 to 8 carbon atoms exemlar conjugated--diolefins ith each'oth'er or with copolymerizable monomeric materialscontain- "ing a single ethylenic linkage; such as acrylopolymers of other conjugated dienes, such as chloroprene and the like.

Although small quantities of a silicon monoxide-ammonia reaction product impart some reinforcing properties to rubbery compositions to which it is added, it is necessary, in order to obtain optimum properties and characteristics in reinforced rubbery compositions, to incor-, porate in the rubbery composition preferably from 40 to 80 parts by weight of a silicon mon-. oxide-ammonia reaction product based on 100 parts by weight of rubbery material.

The following examples are intended merely as illustrations of this invention, and it will be understood that the examples are not intended to limit the scope of the invention;

EXAMPLE 1 A mixture of relatively pure silica sand aridground carbonaceous fuel is heated in an electric arc furnace having an atmosphere which has a relatively low oxygen concentration. The gaseous combustion products which contain gaseous silicon monoxide are discharged immediately after formation into a reaction chamber having an atmosphere which has a high concention of gaseous ammonia, substantially free from oxygen. Preferably the molar ratio of ammonia to gaseous silicon monoxide in the reaction chamher is maintained at about 1:1, although an excess of either reagent may be employed. In order to obtain a product as nearly free from particles of silica as possible, it is preferable that-anexcess of ammonia be present, up to by weight or more.

The ammonia and the gaseous silicon monoxide present in the gaseous products of combustion react rapidly to form a finely-divided generally light-colored to blue-white material resembling amorphous silica in appearance and having a density of from approximately 2.25 to 2.60 grams per cubic centimeter at 30 C. X-ray diffraction analysis indicates that the silicon monoxide-ammonia reaction product is a new composition of matter comprising polymeric silicon oxyimide as evidenced by a "halo pattern indicating an amorphous material having a predominant interatomic spacing of approximately 3.70 Angstrom units. Upon heating the silicon monoxide-ammonia reaction product in air at a temperature of approximately l,000 C. for hours, the reaction product is decomposed and the solid particulate material remaining after the heating process is silica.

A typical example of a rubbery composition embodying my invention using natural rubber as the rubbery material is as follows:

Material Parts by weight Natural rubber 100.0 Silicon monoxide-ammonia reaction prod- The rubber and compounding ingredients were mixed in the usual manner on a roll mill. The rubbery composition was vulcanized in a mold at Tensile Elongation 3009 Strength i ggsi fi Modulus, at Break- 5 2 p. s. i. inglgoiint, percent EXAMPLE 2 The silicon monoxide-ammonia reaction product may be formed as in Example 1.

The following rubber recipe is another typical example of a rubbery composition embodying this invention: v

Material Parts by weight Natural rubber 100.0 Silicon monoxide-ammonia reaction prod- The rubber was placed on a'roll mill and the rubber compounding ingredients were incorporated in the usual manner. The rubber composition was vulcanized in a mold maintained at a temperature of 280 F. for varying lengths of time and the following data were obtained upon testing the vulcanized samples:

Tensile Elon ation vulcanization Time geg ig at the at 280 F. O 5 P 8 fgi Break, percent EXAMPLE 3 The silicon monoxide-ammonia reaction product may be formed as in Example 1.

A typical example of a rubbery composition embodying the silicon monoxide-ammonia reaction product and using synthetic rubber as the elastomeric material is as follows:

The composition was prepared by mixing the ingredients in the usual manner and vulcanizing the composition in a mold at 290 F. for 130 minutes. A vulcanized product having excellent reinforced physical properties, as indicated by tensile strength and elongation measurements, was obtained.

Robbery compositions reinforced with silicon monoxide-ammonia reaction products may be white in color and may be fabricated into any desired configuration by processes commonly employed in the rubber industry for fabricating rubbery articles.

It is clear that obvious modifications and variations may be made without departing from the spirit and scope of my invention as defined in the appended claims.

I claim:

1. A finely-divided amorphous composition of matter comprising a polymeric silicon oxyimide.

2. A finely-divided amorphous composition of matter comprising a polymeric silicon oxyimide, said composition of matter having an average particle diameter of from 5 to 200 millimicrons.

3. The method of making a finely-divided amorphous composition of matter comprising reacting gaseous silicon monoxide with ammonia in an atmosphere substantially free from oxygen.

4. An elastomeric composition comprising a rubbery conjugated diene polymer and a finelydivided amorphous composition of matter comprising a polymeric silicon oxyimide.

5. An elastomeric composition comprising a rubbery conjugated diene polymer and a finelydivided amorphous composition of matter comprising a polymeric silicon oxyimide, said composition of matter having an average particle diameter of from 5 to 200 millimicrons.

6. An elastomeric composition comprising 100 parts by weight of a rubbery conjugated diene polymer and from 40 to 80 parts by weight of a finely-divided amorphous composition of matter comprising a polymeric silicon oxyimide.

7. An elastomeric composition comprising 100 parts by weight of a rubbery conjugated diene polymer and from 40 to 80 parts by weight of a finely-divided amorphous composition of matter comprising a polymeric silicon oxyimide, said composition of matter having an average particle diameter of from 5 to 200 millimicrons.

8. The method of making a vulcanized rubbery composition comprising uniformly dispersing a finely-divided amorphous composition of matter comprising a polymeric silicon oxyimide into a rubbery conjugated diene polymer, and vulcanizing the composition.

9. The method of making a vulcanized rubbery composition comprising dispersing uniformly into a rubbery conjugated diene polymer a finely-divided amorphous composition of matter comprising a polymeric silicon oxyimide, said composition of matter having an average particle diameter of from 5 to 200 millimicrons, and vulcanizing the composition.

10. The method of making a vulcanized rubbery composition comprising dispersing uniformly into 100 parts by Weight of a rubbery conjugated diene polymer from 40 to parts by weight of a finely-divided amorphous composition of matter comprising a polymeric silicon oxyimide, and vulcanizing the composition.

11. The method of making a vulcanized rubber composition comprising dispersing uniformly into parts by weight of a rubbery'conjugated diene polymer from 40 to 80 parts by weight of a finely-divided amorphous composition of matter comprising a polymeric silicon oxyimide, said composition of matter having an average particle diameter of from 5 to 200 millimicrons, and vulcanizing the composition.

12. The method of making a finely-divided amorphous composition of matter comprising reacting gase-ous silicon monoxide and an excess molar quantity of gaseous ammonia together in an atmosphere substantially free from oxygen.

13. A finely-divided amorphous composition of matter having a density from approximately 2.25 to 2.60 grams per cubic centimeter at 30 C. and comprising a polymeric silicon oxyimide having a predominant interatomic spacing of approximately 3.70 Angstrom units.

14. An elastomeric composition comprising a rubbery conjugated diene polymer and a finelydivided amorphous composition of matter having a density from approximately 2.25 to 2.50 grams per cubic centimeter at 30 C. and comprising a polymeric silicon oxyimide having a predominant interatomic spacing of approximately 3.70 Angstrom units.

15. A finely-divided amorphous composition of matter comprising a polymeric silicon oxyimide having a predominant interatomic spacing of approximately 3.70 Angstrom units.

16. A finely-divided amorphous composition of matter comprising a polymeric silicon oxyimide, said composition of matter having an average particle diameter from 5 to 200 millimicrons and having a density of from approximately 2.25 to 2.60 grams per cubic centimeter at 30 C.

17. An elastomeric composition comprising a rubbery conjugated diene polymer and a finelydivided amorphous composition of matter comprising a polymeric silicon oxyimide having a premodinant interatomic spacing of approximately 3.70 Angstrom units, and having an average particle diameter from 5 to 200 millimicrons and having a density of from approximately 2.25 to 2.60 grams per cubic centimeter at 30 C.

DANIEL S. SEARS.

Name Date Von Stroh Sept. 30, 1947 Number 

1. A FINELY-DIVIDED AMORPHOUS COMPOSITION OF MATTER COMPRISING A POLYMERIC SILICON OXYIMIDE,
 4. AN ELASTROMERIC COMPOSITION COMPRISING A DIVIDED AMORPHOUS COMPOSITION OF MATTER COMPRISING A POLYMERIC SILICON OXYIMIDE. 